C08F236/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds

C08F236/02—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds

C08F236/04—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated

C08F236/10—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated with vinyl-aromatic monomers

C08C19/30—Addition of a reagent which reacts with a hetero atom or a group containing hetero atoms of the macromolecule

C08C19/42—Addition of a reagent which reacts with a hetero atom or a group containing hetero atoms of the macromolecule reacting with metals or metal-containing groups

C08C19/44—Addition of a reagent which reacts with a hetero atom or a group containing hetero atoms of the macromolecule reacting with metals or metal-containing groups of polymers containing metal atoms exclusively at one or both ends of the skeleton

C08F36/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds

C08F36/02—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds

C08F36/04—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated

C08F36/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds

C08F36/02—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds

C08F36/04—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated

C08L47/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds; Compositions of derivatives of such polymers

C08F212/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring

C08F212/02—Monomers containing only one unsaturated aliphatic radical

C08F212/04—Monomers containing only one unsaturated aliphatic radical containing one ring

C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group

C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure

Abstract

The invention relates to polymers obtainable by using novel polymerization initiator compounds and optionally chain end modifying agents. The invention further relates to a method of making the initiator compounds and the corresponding polymers, including chain end-modified polymers. The invention, also relates to polymer compositions comprising the polymer of the invention, and further components such, as extender oils, fillers, etc., and to corresponding vulcanized polymer compositions and articles comprising vulcanized parts made from, the vulcanized polymer composition.

Description

POLYMERISATION INITIATORS

FIELD OF THE INVENTION

This invention, relates to polymerization initiators and their preparation. The invention also relates to polymers, including modified (i.e. chain-end modified) polymers, prepared with the initiators of the invention and to polymer compositions made therefrom,. The invention furthermore relates to the use of these compositions in the preparation of vulcanized compositions and articles prepared from the same. The polymer compositions are useful in the preparation of vulcanized and, thus, cross-linked elastomenc compositions having relatively low hysteresis loss, good grip properties and high abrasion resistance. Such compositions are useful in many articles, including tire treads having low heat build-up, low rolling resistance and high abrasion resistance, in combination with a good balance of other desirable physical, and chemical properties, for example, good wet grip, ice grip and tensile strength and excellent processability.

BACKGROUND OF THE INVENTION

Increasing oil prices and national legislation requiring the reduction of automotive carbon dioxide emissions force tire and rubber producers to produce "fuel-efficient" and thus fuel- saving tires. One general approach to obtain fuel-efficient tires is to produce tire formulations which have reduced hysteresis loss. A major source of hysteresis in vulcanized elastomeric polymers is attributed to free polymer chain, ends, i.e. the section of the elastomeric polymer chain between the last cross-link and the end of the polymer chain. This free end of the polymer does not. participate in the efficient elastically recoverable process and, as a result, energy transmitted to this section of the polymer is lost. The dissipated, energy leads to a pronounced hysteresis under dynamic deformation. Another source of hysteresis in vulcanized elastomeric polymers is attributed to an insufficient distribution of filler particles in the vulcanized elastomeric polymer composition. The hysteresis loss of a cross-linked elastomeric polymer composition is related to its tan δ value at 60°C (see ISO 4664-1 :2005; Rubber, Vulcanized or thermoplastic; Determination, of dynamic properties - part 1 ; General guidance). In general, vulcanized elastomeric polymer compositions having relatively small tan δ values at 60 °C are preferred as having lower hysteresis loss. In the final tire product, this translates into a lower rolling resistance and better fuel economy.

It is generally accepted that a lower rolling resistance tire can be made at the expense of deteriorated wet grip properties. For example, if, in, a random, solution styrene-butadiene rubber
(random SSBR), the polystyrene unit concentration is reduced with respect to the total polybutadiene unit concentration, and the 1 ,2-polybutadiene unit concentration is kept constant, the SSBR glass transition temperature is reduced and, as a result, both tan δ at 6(J°C and tan δ at 0°C are reduced, generally coixesponding to improved rolling resistance and deteriorated wet grip performance of the tire. Similarly, if, in a random SSBR, the 1 ,2 -polybutadiene unit concentration is reduced with respect to the total polybutadiene unit concentration, and the polystyrene unit concentration is kept constant, the SSBR glass transition temperature is reduced and, as a result, both tan δ at 60°C and tan δ at 0°C are reduced, generally corresponding to improved roiling resistance and deteriorated wet grip performance of the tire. Accordingly, when assessing the rubber vulcanizate performance correctly, both the rolling resistance, related to tan δ at 60°C, and the wet grip, related to tan δ at 0°C, should be monitored along with the tire heat build-up.

One generally accepted approach for reducing hysteresis loss is to reduce the number of free chain ends of elastomeric polymers. Various techniques have been described in the literature, including the use of "coupling agents" such as tin tetrachloride, which may funettonalize the polymer chain end and react with components of an. elastomeric composition, for example with a filler or with unsaturated portions of a polymer. Examples of such techniques and coupling agents are described in the following patents: U.S. 3,281 ,383; U.S. 3,244,664 and U.S. 3,692,874 (for example, tetrachlorosilane); U.S.. 3,978, 103; U.S. 4,048,206; U.S. 4,474,908; U.S. 6,777,569 (blocked mercapto silanes) and U.S. 3,078,254 (a multi-halogen-substituted hydrocarbon, such as l ,3,5-tri(bromomethyl) benzene); U.S. 4,616,069 (tin compounds and organic amino or amine compounds); and U.S. 2005/0124740. The reference article "Synthesis of end-functionalized polymer by means of living anionic polymerization", Journal of Macromolecular Chemistry and Physics, 197, ( 1996), 3135-3148, describes the synthesis of "polystyrene-containing" and "polyisoprene-containing" living polymers with hydroxy (-OH) and mercapto (-SH) functional end caps, obtained by reaction of living polymers with haloalkanes containing silyl ether and silyl thioether functions. The t e rt i a r y - b u t 1 d i m e t h y 1 s i 1 y 1 (TBDMS) group is preferred as a protecting group for the -OH and -SH functional groups in the termination reactions, because the corresponding silyl ethers and thioethers are foimd to be both stable and compatible with anionic living polymers.
WO 2007/047943 describes the use of a siiane sulfide omega chain end modifier represented by the formula (RO)s(R)ySi-R'-S-SiR3, wherein x is 1 , 2 or 3, y is 0, 1 or 2, x+y=3. R is alkyl, and R' is aryl. alkylaryl or alkyl, to produce a chain end-modified elastomeric polymer, which is used as component in a vulcanized elastomeric polymer composition or a tire tread.

More specifically, according to WO 2007/047943, a siiane sulfide compound is reacted with anionically-initiated living polymers to produce "chain end-modified" polymers, which are subsequently blended with fillers, vulcanizing agents, accelerators or oil extenders to produce a vulcanized elastomeric polymer composition having low hysteresis loss.

The vulcanized elastomeric polymer compositions are described as exhibiting lower tan δ values at 60°C, particularly in comparison with compounds based on corresponding non- modified polymers, without negatively affecting tan δ values at 0°C and processing characteristics. Individual exemplary cured polymer formulations comprising modified polymers are shown to result in reduced tan δ at 60°C and heat build-up values but. equivalent tan δ values at 0°C. They are described as being useful in preparing tire treads having lower rolling resistance, while maintaining good wet grip properties. In case the modifier contains two or three aJkoxy groups (x=2 or 3), the resulting functionalized polymer comprises -Si-OR groups and -S-S1R3 groups, which are converted under suitable conditions, such as typically present during reactive mixing of functionalized polymers with fillers, into silanol groups (-Si-Oil) and thiol groups (-S-H). Silanol groups and thiol groups arc reactive with respect to fillers containing silanol surface groups, such as silica. Thus, the formation of bonds between functionalized polymer and. silica is expected. Although cured rubber hysteresis properties can be improved significantly through application of the technology described in. WO 2007/047943, the impact of the technology is limited due to the fact that only one polymer chain end. can be functionalized. by using the modifier compound described. Accordingly, there is a need for an efficient modification of the second polymer chain end.

There is a need for modification methods and resulting polymers, including modified polymers, which can be used for ilirther optimizing dynamic properties, of vulcanizates containing silica and carbon black, including low hysteresis loss and high abrasion resistance, corresponding to a high wet grip, low rolling resistance and high abrasion resistance in tires. In addition, there is a need to further decrease the vulcanizate heat build-up during thermal exposure and under mechanical stress. These needs have been met by the following invention.
SUMMARY OF THE INVENTION

In a first aspect, the invention provides a polymerization initiator according to Fo:

Formula 1 ,

or Lewis base adducts thereof,

wherein

each M 1 is independently selected from lithium, sodium and potassium;

each R1 is independently selected from (C I -C HJO) alkyl and (C2-C100) alkenyl, optionally substituted with one or more (Q-C12) aryl groups and optionall linked to the carbon atom C by up to 25 monomer units selected from conjugated diene monomers and aromatic vinyl compounds, especially butadiene, isoprene and styrene;

Y3 is selected from a nitrogen atom, a sulfur atom and a silicon atom.; R95 R10 and R1 1 are each independently selected from. (Cj-C|g) alkyl, di(Cs -C6) alkyl amine (only when. Y3 is a silicon atom), (Ce-Cig) aryl, (C7~Ctg) alkylaryl, and, when Y3 is not a silicon atom, ~SiR20R2!R22, wherein R20, R21 and R22 are each independently selected, from (Cr Cig) alkyl,. (Cg-Cig) aryl and (C7-CSg) alkylaryl; t and u are each an integer selected
from 0 and 1 ; and t+u=l when Y3=N, t=u=0 when Y3=S, and t+u=2 when Y3=Si;

Y2 is selected from a nitrogen atom., a sulfur atom and a silicon atom; R6, R'and R8 are each independently selected from (Cj-Cis) alkyl, di(C)-Qs) alkyl amine (only when Y is a silicon, atom), ( ,-Cig) aryl, (C7-Cig) alkylaryl. and, when Y2 is not a silicon atom, -SiR! 7R!8R19, wherein R17.. R!8 and R19 are each independently selected from. (C,- Cig) alkyl, (t Cig) aryl and (C7-Cig) alkylaryl; q and r are each an integer selected from 0 and 1 ; and. qH r=1 when Y2=N, q=r=0 when Y2=S, and q+r=2 when Y2=Si;

In a second aspect, the invention provides a method of making the polymerization initiator of Formula 1 , including Lewis base adducts thereof, comprising the step of reacting (i) a compound of Formul 2

In a third aspect, the invention provides a polymer of the invention, including a modified polymer, which is the reaction product of
i) a polymerization initiator of Formula 1 or a Lewis base adduct thereof and

ii) at least one type of polymerizable monomers selected from conjugated olefins and aromatic vinyl compounds.

In a fourth aspect, the invention provides a method of making the polymer of the invention, including modified polymer, comprising the step of reacting

i) a polymerization initiator of Formula 1 or a Lewis base adduct thereof and

ii) at least one type of polymerizable monomers selected from conjugated olefins and aromatic vinyl compounds.

In a fifth aspect, the invention provides a first polymer composition comprising the polymer of the invention, including modified polymer, and one or more further components selected from (i) components which are added to or formed as a result of the polymerization process used for making the polymer and (ii) components which remain after solvent removal from, the polymerization process. Components which arc added to the polymerization process include, in particular, oils (extender oils), stabilizers and further polymers.

In a sixth aspect, the invention provides a second polymer composition comprising the polymer of the invention, including modified polymer, and one or more fillers. The second polymer composition is the result of mechanical mixing of the polymer of the invention, including modified polymer, as obtained after solvent removal from the polymerization process, and one or more fillers and further optional components.

The first and second polymer compositions may optionally further comprise a least one vulcanizing agent.

In a seventh aspect, the invention provides a vulcanized polymer composition which is obtained by vulcanizing the first or the second polymer composition, which comprises at least one vulcanizing agent.

In an eighth aspect, the invention provides a method of making the vulcanized polymer composition of the seventh aspect, comprising the step of vulcanizing the first or second polymer composition, which comprises at least one vulcanizing agent.
In a ninth aspect, the invention provides an article comprising at least one component formed from a vulcanized polymer composition of the invention. The article may be, for example, a tire, a tire tread, a tire side wall, an automotive part, a footwear component, a golf ball, a belt, a gasket, a seal or a hose.

The polymerization initiator of the first aspect of the invention is a compound of Formula 1 as defined above. The polymerization initiator of the invention includes at least two carbanions 10 which are each linked to a metal atom. M1.

In one preferred embodiment, M! is lithium;

R1 is identical and is selected from (CpCio) alkyl;

each R12 is independently selected from hydrogen and (Ci-Cjo) alkyl, preferably hydrogen; i s Y' and Y2 are identical;

R3, R4 and Rs are each independently selected from (C pQs) alkyl and, when Y1 is not a silicon atom., -SiR14Rl 5R16, wherein R14, R15 and R16 are each independently selected from (C C|g) alkyl;

each E is independently selected from (Ci~Cjg) alkyl;

20 each F is independently selected from -Y2(R6)(R7)q(R8)r5 wherein R6, R7 and R8 are each independently selected from (Ci-Cjg) alkyl and, when Y ' is not a silicon atom, -SiR R R" , wherein R175 R18 and R19 are each independently selected from. (C|-Cig) alkyl;

p is an integer selected from. 1 , 2 and 3;

K. is selected from nitrogen and >C-H; and

25 all other substituents or groups are as generally defined for Formula 1.

In. one embodiment, Y1, Y2 and Y3 are each a sulfur atom. In another embodiment, Y1, Y2 and. Y3 are each a. nitrogen atom... In yet another embodiment, Y1, Y2 and Y3 are each a silicon atom.

30 In one preferred embodiment, referred to as "Embodiment 1 ", the polymerization initiator of Formula 1 is represented by the following Formula 5:

Formula 5,

or a Lewis base adcluct thereof,

wherein

M is lithium;

each R1 is independently selected from (Cj-Cig) alkyl;

p is an an integer selected from 1 , 2 and 3;

is selected from nitrogen and >C-H; and

all other substituents or groups are as generally defined for Formula 1 above.

In one embodiment of the polymerization initiator of Formula 5,

each R 1 is independently selected from. (C|-C7) alkyl;

R12 is hydrogen;

R.3, R4 and R.s are each independently selected from (Ci-Cio) alkyl and, when Y1 is not a. silicon atom, -SiR,4R, sR165 wherein R!4, R! 5 and R!6 are each independently selected from

alkyl; and

R.6, R7 and. R8 are each independently selected from (Ci-Ci0) alkyl and, when. Y2 is not a silicon atom, -SiR17Rl 8R19, wherein R17, R18 and R.19 are each independently selected from (Ci-C|6) alkyl

In a preferred embodiment of the polymerization initiator of Formula 5,

each R 1 is independently selected from (C|-Cio) alkyl;

R12 is hydrogen;

R3, R.4 and. R5 are each independently selected from (Ct-Cjg) alkyl and, when Υ' is not a silicon atom, -SiR, 4R, 5R16, wherein R14, R1 ' and R16 are each independently selected from (Ci-Cio) alkyl;

R6, R.7 and R8 are each independently selected from. (C,-Ci8) alkyl and, when Y2 is not a silicon atom, -SiRi 7R18R19, wherein R175. R.18 and R19 are each independently selected from (C Ci0)
alkyl;

m and p arc each independently selected from an integer of 1 and 2; and

all other substituents or groups are as generally defined herein for Embodiment 1 .

In another preferred embodiment, referred to as "Embodiment 2", the polymerization initiator of Formula 1 is represented by the following Formula 6:

Formula 6,

or a Lewis base adduct thereof,

wherein

M1 is lithium;

each R1 is independently selected from (C |-C |0) alkyl;

R12 is hydrogen;

R\ R4 and R5 are each independently selected from. (Cj -Cjg) alkyl and, when Y1 is not a silicon atom, -SiR14R, 5R16, wherein R14, R15 and R16 are each independently selected from (CrCio) alkyl;

m and p are each independently an. integer selected from 1 and 2;

R6, R.7 and Rs are each independently selected from (C Cjg) alkyl and, when Y2 is not a silicon atom, -SiR | 7R'V y wherein R17, R18 and R19 are each independently selected from (Ci-Cio) alkyl; and

ail other substituents or groups are as generally defined for Formula 1 above,

I n one embodiment of the polymerization initiator of Formula 6,

each R1 is independently selected, from (C1 -C7) alkyl;

R12 is hydrogen;

R R4 and Rs are each independently selected from. (C[-Cm) alkyl and, when Y1 is not a silicon atom, -SiRi4R15R16, wherein R14, R15 and R1 6 are selected from (Ci -C|6) alkyl; and

R6, R.7 and I are each independently selected from (Ci-C10) alkyl and, when Y2 is not a silicon
atom, -SI I 7R! 8R'9, wherein R17, R18 and R19 are each independently selected from (C,-C,0) alkyl.

In more specific embodiments, the polymerization initiator is represented by the following Formula 17, 18 or 19:

Formula 1.7

Formula 18

Formula 19

or Lewis base adducts thereof,

wherein

M1 is lithium.;

each R1 is independently selected from (Ci-Cig) alkyl; and

all other substituents or groups are as generally defined for Formula 1 above.

In one embodiment of the polymerization initiator represented by Formula 17, 18 or 19, each R1 is independently selected from (Ci-Cio) alkyl;

R is hydrogen;

R :. R4 and R5 are each independently selected from (Ci-Cjg) alkyl and, when Y1 is not a silicon atom, -SiR,4R, 5R16; wherein R14, R15 and R16 are selected from (C,-Ci0) alkyl; and
7 ¾ "7

R , R and R are each independently selected from (Cj-Cig) alkyl and, when Y~ is not a silicon atom, -SiR17R, 8R19, wherein R17, R18 and R19 are each independently selected from (C,-C!0) alkyl.

In one embodiment of Formula 17, 18 or 19,

each R 1 is each independently selected from (C1-C7) alkyl;

12

R is hydrogen:

R R4 and R5 are each independently selected from (CpCio) alkyl and, when Y 1 is not a silicon atom, -SiR,4Ri SR16; wherein R14, R15 and Ri 6 are selected from (Ci-C10) alkyl; and

R\ R7 and R8 are each independently selected from (Cj-Cig) alkyl and, when Y2 is not a silicon atom, -SiR, 7R, 8R19, wherein R17. R18 and R19 are each independently selected from (Ci-C! 0) alkyl.

Among the polymerization initiators represented by Formulas 1 , 5, 6, 17, 1 8 and 19, those of Formulas 6. 17, 18 and 1 9 are preferred, and those of Formula 1 8 are most preferred.

LEWIS BASE

Suitable Lewis bases for forming Lewis base adducts with the polymerization initiator of Formula 1 of the invention, including embodiments thereof, such as those of Formulas 5, 6 and

17 to 19, include those described in the Section "Randomizer Agents" as well as those according to the following Formulas 20 and 21 :

Preferred Lewis bases for use in the polymerization initiator of Formula 1 of the invention are those of Formulas 20 and 21 , and particularly preferred, are those of Formula 21 , wherein z is an. integer selected from 1 , 2 and 3.

METHOD OF MAKING THE POLYMERIZATION INITIATOR

The polymerization initiators of the invention are produced, as the second aspect of the invention, from the corresponding polymerization initiator precursor compounds of Formula 2, which include at least two olefinic bonds in conjugation with an aromatic ring.

The method of making the polymerization initiator of Formula ! , including Lewis base adducts thereof, comprises the step of reacting an initiator precursor compound of Formula 2 with at least one compound of Formula 3 and optionally a Lewis base. The reaction is usually carried out at a ratio of compound of Formula 3 to compound, of Formula 2 in terms of mole equivalents of from 1 , 1 to 16 (1.1 : 1 to 16:1 ), preferably from 1.5 to 4 and even more preferably from 1.8 to 2.2. It is preferably performed in a nonpolar solvent, including hydrocarbon solvent, including aliphatic and aromatic solvent, preferably aliphatic solvent, such as hexane, heptane, pentane, isopar, cyclohexane and methylcyclohexane, and is usually carried out for a period of from 2 seconds to 3 days, preferably from 5 seconds to 2 days, even more preferably from 10 seconds to 10 hours, at a temperature ranging from. -60°C to 1 30°C5 preferably from 0°C to 100°C and even more preferably from. 20°C to 70°C.

A polymerization initatior of the invention in which R! is linked to the carbon, atom C by up to 25 monomer units can be obtained by prior reaction of the compound of Formula 3 with monomers selected from conjugated, diene monomers and. aromatic vinyl compounds, especially butadiene, isoprene and styrene, thus producing a compound of Formula 3 wherein R1 is linked to Mf by an oligomeric chain of up to 25 monomer units. Subsequently, this "oligomer" of Formula 3 is reacted with the initiator precursor compound of Formula 2, as described herein.

The Lewis base may be added to the precursor compound of Formula 2 prior to the addition of and reaction with the compound of Formula 3, so as to be present in the reaction from the beginning. Alternatively, it may be added during the reaction or after completion of the
reaction. Any of these alternative additions will result in the formation of a Lewis base adduct of the polymerization initiator of Formula 1 , When a Lewis base is present in the reaction for making the polymerization initiator of the invention, it is usually used at a. ratio of initiator precursor compound of Formula 2 to Lewis base in terms of mole equivalents of from 0.1 to 20, preferably from 0.4 to 5.0 and even more preferably from 0.5 to 3,0.

For increasing the storage stability (shelf life) of the polymerization initiator, it is possible to contact the resulting reaction mixture containing the polymerization initiator and including alkali metal M1 with a limited amount of one or more po!ymerizable monomers selected from conjugated diene monomers and aromatic vinyl compounds, preferably selected from styrene, butadiene and isoprene. For this purpose, an amount of up to 1000 equivalents, preferably up to 200 equivalents, most preferably up to 75 equivalents of polymerizable monomer per alkali metal equivalent is suitably used.

Preferred embodiments of the reaction and of the compounds of Formulas 2 and 3 are those which provide a polymerization initiator of Formula 1 and embodiments thereof as defined herein in the description of the polymerization initiator.

In one embodiment, referred to as "Embodiment 3", the polymerization initiator of Formula 5

Preferred embodiments of the reaction of Embodiment 3 and of the compounds of Formulas 7 and 3 are those which provide a polymerization initiator of Formula 5 (Embodiment 1) and
embodiments thereof as defined herein in the description of the polymerization initiator.

In one embodiment, the polymerization initiator of Formula 17 as defined above is obtained by reacting a compound of the following Formula 22

with at least one compound of Formula 3, wherein M1 and R1 are as defmed for Formula 17, and optionally a Lewis base.

In one embodiment, the polymerization initiator of Formula 18 as defined above is obtained by reacting a compound of the following Formula 23

Formula 23

wherein R\ R\ R°, R , R'\ m and p are as defined for Formula 18,

with at least one compound of Formula 3, wherein M1 and R1 are as defined for Fonnula 18, and optionally a Lewis base..

In one embodiment, the polymerization initiator of Formula 19 as defined above is obtained by reacting a compound of the following Formula 24

Formula 24

wherein R" , R , R m and p are as defined for Formula 1 ,

with at least one compound of Formula 3, wherein M1 and R1 are as defined for Formula 9, and optionally a Lewis base.

Preferred embodiments of the reaction and of the compounds of Formula 22, 23 or 24 and

Formula 3 are those which provide a polymerization initiator of Formula 17, 18 or 19, respectively, and embodiments thereof as defined herein in the description, of the polymerization initiator.





POLYMER

The polymer of the third aspect of the invention, including modified polymer, is the reaction product of:

i) a polymerization initiator of Formula 1 or a Lewis base adduct thereof and ti) at least one type of polymerizable monomers selected from conjugated olefins and aromatic vinyl compounds.

Generally, for producing a polymer of the invention, one or more polymerization initiators of the invention may be used.

In specific embodiments of the polymer of the invention, the polymerization initiator used for its preparation is one or more selected from, the embodiments and preferred embodiments as defined herein in the description of the polymerization initiator.

In one embodiment of the polymer of the invention, referred to as "Embodiment 4", the polymerization initiator is a compound of Formula 5 or a Lewis base adduct thereof, as defined herein as "Embodiment 1 " in the description of the polymerization initiator and including embodiments and preferred embodiments thereof.
In another embodiment of the polymer of the invention, the polymerization initiator is a compound of Formula 6 or a Lewis base adduct thereof, as defined herein as "Embodiment 2" in the description of the polymerization initiator and including embodiments and preferred embodiments thereof.

In yet another embodiment of the polymer of the invention, the polymerization initiator is selected from a compound of Formula 1 7. 18 or 19 or a Lewis base adduct thereof, as defined herein in the description of the polymerization initiator and including embodiments and preferred embodiments thereof.

The polymerization initiator of Formula 1 , including the embodiments of Formulas 5, 6, 17, 18 and 19, may be reacted, optionally in the presence of a Lewis base, with a fraction of the total amount of monomers required for making the desired polymer and may then be stored for an amount of time, for example from seconds to weeks, before further reacting it with the remaining amount of monomers to complete the polymerization process. In one embodiment, the fraction of the total amount of monomers is from, 1 to 40 monomer equivalents based on the amount of polymerization initiator.

In a preferred embodiment, the polymer of the invention is a modified polymer and is the product of

firstly reacting a polymerization initiator of Formula 1 , including Formulas 5, 6, 17, 18 and 19 and embodiments thereof, or a Lewis base adduct thereof with at least one type of polymerizable monomers selected from conjugated olefins and aromatic vinyl compounds, thus forming an omega,omegaT-dianionic living polymer, and

further reacting the omega,omega'-dianionic living polymer with a chain-end modifying agent as described below, thus forming the modified polymer as an omega,omega' -modified polymer which is modified with at least two polymer chain ends.

The polymer, including modified polymer, according to the third aspect of the invention can be represented structurally, for example, by the following Formulas PI to P6:

Formula P2,

Formula P3,

Formula P4,

Formula P5,

Formula P6

and Lewis base adducts thereof,

wherein

P1 and P2 are each independently a polymer chain formed from monomer units selected from conjugated olefins and aromatic vinyl compounds, especially butadiene, isoprene, styrene and alpha-methyl styrene, wherein the total number of monomer units per polymer molecule may range from 10 to 50.000, preferably from. 20 to 40.000;

W' and W2 are each independently selected from hydrogen and a chain end modifying group produced by reaction of the chain end of P and/or P with a chain-end modrlymg agent as described herein; and

Polymers and modified polymers of Formulas P4, P5 and P6 are preferred.

Specific preferred polymers and modified polymers include the following ones, including





Moieties resulting from the process of chain end modification using chain end modifying agents having a terminal trihydrocarbylsilyl group, including trialkylsilyi, trialkylarylsilyl and triarylsilyl; trihydrocarbylstannyl group, including trialkyistannyl, trialk larylstannyi and triarylstannyl; dihydrocarbyisi!endiyl group, including dialkylsilendeyl, dialkylarylsilendiyl and diarylsilendiyl or dihydrocarbylstannendiyl group, including dialkylstannendiyl, dialkylaryistannendiyl and diary lstannendiyl, are believed to function as protective groups,, which prevent unintended subsequent reaction of the polymer chain. Such protective groups may be removed by exposure to a compound containing a reactive hydroxyl group (-OH), such as water, alcohols, anionic acids or organic acids (for example hydrochloric acid, sulfuric acid or carboxylic acids). Such conditions are typically present during vulcanization. In those cases where the terminal group of the chain-end modifying compound is sulfide-] inked, the exposure to a reactive hydroxy! group and deprotection will result in the formation of an unprotected thiol group (-SH) as the terminal group of the polymer chain. Depending on the work-up conditions for the modified polymer (e.g., steam stripping), both the unprotected modified and the protected modified polymer may be present, it is believed that certain terminal groups of the polymer, such as an unprotected thiol group, are reactive towards fillers such as silica and/or carbon black, which may result in a more homogeneous distribution of the filler within a polymer composition.

The reaction product as a chain-end modified polymer typically contains silanol groups and alkoxysilyl groups in a total amount from 0.0001 to 3.00 mmol/gram of polymer, preferably from 0.0005 to 1.8 mmol/gram, more preferably from 0.0010 to 1.0 mmol/gram and even more preferably from 0.0020 to 0.2 mmol/gram.

The reaction product as a chain-end modified polymer preferably contains sulfide groups (in the form of thiol groups and/or sul fide-linked protective groups) in a total amount of from 0.0001 to 0.80 mmol/gram of polymer, preferably from 0.0005 to 0.50 mmol/gram, more preferably from 0.0010 to 0.30 mmol/gram and even more preferably from 0.0020 to 0.20 mmol/gram of polymer.

For most applications, the polymer is preferably a homopolymer derived from a conjugated diolefin, a copolymer derived from a conjugated diolefin monomer with an aromatic vinyl monomer and/or a terpolymer of one or two types of conjugated diolefins with one or two types of aromatic vinyl compounds. Examples of particularly useful polymers include homopolymcrs of butadiene or isoprcne and random or block eo- and terpolymers of butadiene, isoprene and styrene. especially a random copolymer of butadiene with isoprene and a random. or block copolymer of butadiene with styrene.

Although there are no specific limitations regarding the amount of aromatic vinyl monomer used in the polymer, for most applications aromatic vinyl monomers constitute from. 1 to 60%, preferably from 2 to 55% and more preferably from 5 to 50% by weight, based on the total weight of the polymer. An amount of less than 2% by weight may lead to a deteriorated balance of rolling resistance, wet skid and. abrasion resistance and to reduced tensile strength, whereas an amount of more than 60% by weight may lead to increased hysteresis loss. The
polymer may be a block or random copolymer of an aromatic vinyl monomer, and preferably 40% by weight or more of the aromatic vinyl monomer units are linked singly, and 10 % by weight or less are polymeric "blocks" of eight or more aromatic vinyl monomers linked, successively (the length of successively linked aromatic vinyl units can be measured by an ozonolysis-gel permeation chromatography method developed by Tanaka ct al. (Polymer. Vol. 22, pp. 1721 -1723 (1981 )). Copolymers outside this range tend to exhibit increased hysteresis loss.

Although there are no specific limitations regarding the content of 1 ,2-bonds and/or 3,4-bonds (hereinafter called "vinyl bond content") of the conjugated diolefin portion of the polymer,, for most applications the vinyl bond content is less than 90 % by weight, particularly preferably less than 80 % by weight (based on. the total weight of the polymer). If the vinyl content in the polymer exceeds 90 % by weight, the resulting product may exhibit deteriorated tensile strength and. abrasion resistance and a relatively large hysteresis loss.

Suitable aromatic vinyl compounds include styrcne. C alkyl-substituted styrene, such as 2- methylstyrene, 3 -methyl styrene, 4-methylstyrene, 2,4-dimethylstyrene, 2,4,6-trimethylstyrene, a-methyi styrene and stilbene, 2,4-diisopropylstyrene, 4-tert-butylstyrene, vinyl benzyl dimethylamine, (4-vinyIbenzyl)dimethyl aminoethyl ether, N.N-dimethylaminoethyl styrene, tert-butoxystyrene and vinylpyridine and a combination of two or more thereof, Styrene is a particularly preferred aromatic vinyl compound.
In addition to the above-mentioned conjugated olefins and aromatic vinyl compounds, it is possible to make use of one or more monomers selected from olefins and nonconjugated dioiefins, such as C2.C20 oc-olefms and non-conjugated C4.C20 diolefins, especially norbornadiene, ethylidenenorbornene. 1 ,4-hexadiene, 1 ,5-hexadiene, 1 ,7-octadiene, 4- vinylcyclohexene and divinylbenzene including 1 ,2-divinylbenzene, 1,3 -divinylbenzene and 1 ,4-divinylbenzene,

In one embodiment, the amount of divinylbenzene, including 1 ,2-divinylbenzene, 1 ,3- divinylbenzene and 1 ,4-divinyl benzene, is I mol% or less (based on the total molar amount of the monomers used to make the polymer).

CHAIN END MODIFYING AGENTS

For further control of polymer properties, one or more chain end modifying agents (or briefly "modifying agents") can be used for reaction with the terminal ends of the polymer chain(s) in the polymer of the invention. Generally, silane-sulfide omega chain end modifying agents such as disclosed in WO 2007/047943, WO 2009/148932, US 6,229,036 and US 2013/0131263, each incoiporated herein by reference in its entirety, can be used for this purpose, namely by reaction with the polymer (living anionic polymer) obtained by reaction of the polymerization initiator compound of the invention with a conjugated olefin or aromatic vinyl compound as the monomer component.

In a preferred embodiment, the chain end modifying agent is selected from one or more of the chain end modifying agents represented by the Formulas 8, 9, 10, 1 1, 12, 13, 14, 15 and 16 below and Lewis base ad ducts thereof.

Formula 8

In Formula 8, MJ is a silicon atom or a tin atom;

T is at least divalent and is selected from. (C Cjg) aryl, (CVQg) alkylaryl and (CpCis) alkyl, wherein each group is optionally substituted with one or more groups selected from difCi-C? hydrocarbyl)amino, bis(tri(Ci-C i2 alky!)silyI)amino, tris(Cj-C7 hydrocarbyl)silyl, (C7-Cig)
alkylaryl and (Ce-Cig) aryl;

U is at least divalent and is selected from (C6-C|g) aryl, (C7-Cig) alkylaryl and (CrCi g) alkyl, wherein each group is optionally substituted with one or more groups selected from di(Ci-C7 hydrocarbyl)amino, bis(trt(C i -C 12 alkyl)silyl)amino, tris(Ci-C7 hydrocarbyi)siIylf (Cy-Cig) alkylaryl and (C6-Cig) aryl;

In Formulas 10 and 1 1 , V is at least divalent and is selected from (CVCjg) aryl, (CVCig) alkylaryl and (CpCig) alkyl, wherein each group is optionally substituted with one or more groups selected from di(Ci-C7 hydrocarbyl)amino, bis(tri(Ci-Ci2 alkyl)si!yl)amino, tris(CrC7 hydrocarbyl)silyi, (C7-Cjg) alkylaryl and (Cs-Cig) aryl;
R3s is independently selected from (CVQ) alkyl, (C6-Cis) aryl and (C7-Cjg) alkylaryl;

R50 is at least divalent and is selected from (C6-Cjg) aryl, (C7-Cj g) alkylaryl and (Ci -Cjg) alkyl, wherein each group is optionally substituted with one or more groups selected from dI(Cj-C7 hydrocarbyl)amino, bis(tri(Ci -Ci2 alkyl)silyl)amino, tris(CrC7 hydrocarbyl)silyl, (C7-Cig) alkylaryl and (C6-C jg) aryl.

W is at least divalent and is selected from (C^-Cig) aryl, (C7-C(g) alkylaryl and (Cj-Cig) alkyl, wherein each group is optionally substituted with one or more groups selected from di(Ci-C7 hydrocarbyl)amino, bis(tri(C] -C i 2 alkyl)silyI)amino, tris(Ci-C7 hydrocarbyl)silyl, (C7-Cis) alkylaryl and (Ce-Cjg) aryl;

k is selected from 0, 1 and 2; 1 is selected from 1 , 2 and 3 ; k+l=3; and v is selected from 1 to 20;

F and F are independently selected from hydrogen, hydroxy, chlorine, bromine, iodine, -Si,R5 R53R54, wherein R52 Rs\ R54 are the same or different and are as defined, for Formulas 12 and 13, vinyl, (C6-C i 6) aryl, (C7-C |6) alkylaryl and (Cj-Cie) alkyl, wherein each hydrocarbyl group is optionally substituted with one or more groups selected from hydroxyl, di(Ci-C7 hydrocarbyl)amino, bis(tri(Ci-C|2 alkyl)silyl)amirio and an epoxy group.

If more than one chain end modifying agent is used for the purpose of chain end modification, the chain end modifying agents can be added one after another to a solution of the living anionic polymer, or they can be mixed together before adding the resulting mixture to a solution of the living anionic polymer.

The chain end modifying agents may be added intermittently (or at regular or irregular intervals) or continuously during the polymerization, but are preferably added at a conversion rate of the polymerization of more than 80 percent and more preferably at a conversion rate of more than 90 percent. Preferably, a substantial amount of the polymer chain ends is not terminated prior to the reaction with the chain end modifying agent; that is, living polymer chain ends are present and are capable of reacting with the modifying agent. The chain, end modification reaction may occur before, after or during the addition of any coupling agent. Preferably the chain, end, modification reaction is completed after the addition of any coupling, agent. See, for example, WO 2009/148932, incorporated herein by reference.

In one embodiment, more than 20 percent, preferably more than 35 percent and even more preferably more than 50 percent of the polymer chains, as determined by GPC, formed, in the
course of the polymerization process, are linked with a chain end modifying agent process of polymer chain end modification.

In one embodiment, more than 50 percent, preferably more than 60 percent and more preferably more than 75 percent, as determined by GPC, of the living polymer of the invention (still remaining after the coupling reaction) react with a chain end modifying agent.

PROCESS OF CHAIN END MODIFICATION

The polymerization initiator of the invention reacts with monomers to form an "omega,omega'- carbanionic" living polymer molecule of the invention. The reaction of at least one living polymer molecule with at least one equivalent of chain end modifying agent results in a modified polymer molecule. In case both polymer chain ends of a linear polymer molecule (comprising two omcga,omega' carbanionic polymer chain end positions) are modified with a chain end modifying agent, an omega,omega'-dimodified linear polymer molecule is formed. Thus, each carbanionic polymer chain end reacts with one equivalent of chain end modifying agent. If coupling agents (as described herein) are reacted with one or both of the carbanionic polymer chain end positions, a branched modified polymer molecule is formed. This can also be formed when monomers capable of reacting with more than one growing polymer chain, such as divinylbenzene, are added to the polymerization mixture at any time in the polymerization.

The chain end modifying agent may be added directly to the polymer solution without dilution; however, it may be beneficial to add the modifying agent in dissolved form, such as in an inert solvent (e.g., cyclohexane). The amount of chain end modifying agent to be added to the polymerization may vary depending on the monomer species, coupling agent, chain end modifying agent, reaction conditions and desired polymer properties, but is generally from 0.1 to 5 mol-equivalent, preferably from 0.2 to 4.0 mol-equivalent and most preferably from 0.5 to 3.0 mol-equivalent per mol equivalent of alkali metal in the initiator compound. The polymer chain end modification reaction may be carried out at a temperature ranging from 0°C to 150°C, preferably from 15°C to 120°C and even more preferably from. 40°C to 100°C. There is no limitation as regards the duration of the chain end modification reaction. However, with respect to an economical polymerization, process, for example, in the case of a batch polymerization process, the chain end modification reaction is usually stopped at about 5 to 60 minutes after the addition, of the modifying agent.
A method for making the modified polymer of the invention comprises at least the following steps A through C. Step A: reacting the polymerization, initiator of the invention as represented by Formula I , 5, 6, 17. 18 or 19 {each as defined herein), preferably by Formula 6, 1 7, 18 or 19, with one or more polymerizable monomers selected from conjugated olefins and aromatic vinyl compounds, preferably selected from butadiene, styrene, isoprene, alpha methyl-styrene and combinations thereof, in a polymerization solvent. Suitable polymerization solvents include non-polar aliphatic and non-polar aromatic solvents, preferably hexane, heptane, butane, pentane, isopar, cyclohexane, toluene and benzene.

Step B: optionally reacting part of the polymer molecules of the reaction product of step A with at least one type of coupling agent selected from SnC , (Ri)3SnCl,

The coupling agents may be added intermittently (or at regular or irregular intervals) or continuously during the polymerization, but are preferably added at a conversion rate of the polymerization of more than 80 percent and more preferably at a conversion rate of more than. 90 percent. The coupling agent will typically be added only after a high degree of conversion has already been achieved.

For example, a coupling agent can be continuously added during the polymerization, in cases where asymmetrical coupling is desired. Such continuous addition is normally carried out in a reaction zone separate from the zone where the bulk of the polymerization is taking place. The
coupling agent can be added in a hydrocarbon solution, for example, in cyclohexane, to the polymerization admixture, with suitable mixing for distribution and reaction. Typically, from 0.01 to 2.0 mol, preferably from 0.02 to 1.5 mol and more preferably from 0.04 to 0.6 mol of the coupling agent is used for every 4.0 moles of living anionic polymer chain ends.

Preferably, a substantial amount of the polymer chain ends is not terminated prior to the reaction with the coupling agent; that is, living polymer chain ends are present and capable of reacting with the coupling agent in a polymer chain coupling reaction. The coupling reaction occurs before, after or during the addition of any chain end modifying agent. The coupling reaction is preferably completed prior to the addition of the chain end modifying agent. In some embodiments, between 5 and 20 percent of the living polymer chain ends, as determined by GPC, have reacted with coupling agent prior to the addition of the chain end modifying agent. In other embodiments, between 20 and 35 percent of the living polymer chain ends have reacted with coupling agent prior to the addition of the chain end modifying agent. In yet another embodiment, between 35 and 50 percent of the living polymer chain ends have reacted with coupling agent prior to the addition of the chain end modifying agent.

A combination of different coupling agents such as BuiSnCfe and SnCl^; Me2SiC¾ and

Si(OMe) ; Me2SiCl2 and SiCl4; SnCl4 and Si(OMe)4; SnCl4 and SiCl4, can also be used to couple polymer chains. It is particularly desirable to use a combination of tin and silicon coupling agents in tire tread compounds that contain both silica and carbon black. In such case, the molar ratio of the tin to the silicon compound will normally be within the range of from 20:80 to 95:5; more typically from. 40:60 to 90: 10 and preferably from. 60:40 to 85: 15. Most typically, an amount of from about 0.001 to 4.5 mmol of coupling agent is employed per 100 grams of polymer, ft is normally preferred to utilize from about 0.05 to about 0.5 mmol of coupling agent per 100 grams of polymer to obtain, the desired Mooney viscosity and to enable subsequent chain-end funetiona!ization of the remaining living polymer fraction. Larger quantities tend to produce polymers containing terminally reactive groups or insufficient coupling and only enable an insufficient chain end modification.

The polymer coupling reaction may be carried out in a temperature range of from. 0°C to 150°C, preferably from 15°C to 120°C and even more preferably from 40°C to 100°C. There is no limitation for the duration of the coupling reaction. However, with respect to an. economical
polymerization process, for example in the case of a batch polymerization process, the coup! reaction is usually stopped at about 5 to 60 minutes after the addition of the coupling agent.

METHOD OF MAKING POLYMER

The method of making the polymer according to the fourth aspect of the invention comprises the steps of reacting

i) a polymerization initiator of Formula 1 or a Lewis base adduct thereof and ii) at least one type of polymerizable monomers selected from conjugated olefins and aromatic vinyl compounds.

In specific embodiments of the method of making the polymer, the polymerization initiator is one or more selected from the embodiments and preferred embodiments as defined herein in the description of the polymerization initiator, in one embodiment of the method of making the polymer of the invention, referred to as "Embodiment 5", the polymerization initiator is a compound of Formula 5 or a Lewis base adduct thereof, as defined herein as "Embodiment 1 " in the description of the polymerization initiator and including embodiments and preferred embodiments thereof.

In another embodiment of the method of making the polymer, the polymerization initiator is a compound of Formula 6 or a Lewis base adduct thereof, as defined herein as "Embodiment 2" in the description of the polymerization initiator and including embodiments and preferred embodiments thereof,

Jn yet another embodiment of the method of making the polymer, the polymerization initiator is selected from, a compound of Formula 17, 18 and 1 or a Lewis base adduct thereof, as defined herein, in the description of the polymerization initiator and including embodiments and preferred embodiments thereof.

In a preferred embodiment, the method of making the modified polymer comprises the steps of firstly reacting a polymerization initiator of Formula 1 , including Formulas 5. 6, 17, 18 and 19 and embodiments thereof, or a Lewis base adduct thereof with at least one type of polymerizable monomers selected from conjugated olefins and aromatic vinyl compounds, thus forming an omega,omega'-dianionic living polymer, and
further reacting the omega,omega'-dianionic living polymer with a chain-end modifier compound as described below, thus forming the modified polymer as an omega,omega'- modified polymer which is modified at at least two polymer chain ends. The method of making the polymer is conventionally carried out in a polymerization solvent as a solution polymerization, wherein the polymer formed is substantially soluble in the reaction mixture, or as a suspension/slurry polymerization, wherein the polymer formed is substantially insoluble in the reaction medium. Suitable polymerization solvents include non-polar aliphatic and non-polar aromatic solvents, preferably hexane, heptane, butane, pentane, isopar, cyclohexane, toluene and benzene. The solution polymerization normally takes place at lower pressures, preferably below 10 MPa, preferably in a temperature range of from 0 to 120°C. The polymerization is generally conducted under batch, continuous or semi-continuous polymerization conditions. Generally applicable information about the polymerization technologies including polymerization initiator compounds; polar coordinator compounds and accelerators, each to increase the reactivity of the initiator, to randomly arrange aromatic vinyl com/pounds, to randomly arrange 1 ,2-polybutadiene or 1 ,2-polyisoprene or 3,4-polyisoprene units introduced in the polymer; the amounts of each compound; monomer(s); and suitable process conditions are described in WO 2009/148932, fully incorporated herein by reference.

The method of making the polymer in accordance with the invention will conventionally provide the polymer of the invention, including modified polymer, in the reaction solvent, optionally together with additional (non-inventive) non-modified linear, branched and coupled polymer molecules and additional (non-inventive) modified polymer molecules, with all polymer molecules being made from living polymer chains formed in the polymer polymerization process. The modified polymer molecules of the invention may be formed by the modification of living polymers using modifying agents as described herein. The additional (non-inventive) non-modified and additional (non-inventive) modified polymer molecules are not linked to an initiator compound of the invention and may be the result of using (non- inventive) initiator compounds containing a polar group, living polymer chain-terminating or chain-end modification reactions, chain transfer reactions or living polymer chain coupling reactions, the latter optionally being performed through the use of one or more coupling agents as described herein. The "additional non-modified polymer molecules" or "additional modified
polymer molecules" constitute components which are formed as a result of the polymerization process and which remain after solvent removal from the polymerization process. The polymer or modified polymer of the invention typically constitutes at least 10% by weight of the total polymer produced in the method of the invention, preferably at least 40% by weight, more preferably at least 60% by weight and most preferably at least 80% by weight. The additional modified or non-modified polymer, in contrast, usually constitutes 1% by weight or more of the total polymer produced in the method of the invention, typically 5% by weight or more and even more typically 10% by weight or more, POLYMER COMPOSITIONS

The first polymer composition according to the fifth aspect of the invention comprises the polymer of the invention, including modified polymer, and one or more further components selected from (i) components which are added to or formed as a result of the polymerization process used for making the polymer and (ii) components which remain after solvent removal from the polymerization process. Generally, the first polymer composition is the solvent-free result of the method of making the polymer, further comprising components selected from, oils (extender oils), stabilizers and further (non-inventive) polymers. Suitable oils are as defined herein. The further polymers can be made separately, for example in a. different polymerization reactor, in solution and can be added to the reactor prior to completion of the polymer manufacturing process for the polymer.

The first polymer composition of the invention, as obtained after removal of solvent and process water from the polymerization, process, preferably has a Mooney viscosity (ML 1 +4, 100°C, as measured in accordance with ASTM D 1646 (2004) using a Monsanto MV2000 instrument) of up to 150, preferably from 20 to 120 and more preferably from 30 to 100. If the Mooney viscosity of the polymer composition is more than 150, the processability, as reflected by filler incorporation and heat build-up in the internal mixer, banding on the roll mill, extrusion rate, extrudate die swell, smoothness, etc, is likely to be negatively affected because the compounding machinery used by the tire manufacturer is not designed to handle such high Mooney rubber grades, and. the cost of processing increases. In some cases a Mooney viscosity of less than 20 may not be preferred due to increased tack and cold flow of the uncrosslinked polymer, resulting in difficult handling, poor green strength and poor dimensional stability during storage. In other cases, when the polymer composition is used as a softener,
compatibilizer or processing aid in polymer formulations, a Mooney viscosity of .less than 20 may be preferred.

The preferred molecular weight distribution of the polymer composition as obtained after solvent removal from the pol meraiztion process, reflected by the ratio of weight average molecular weight to number average molecular weight (Mw/M„), ranges from 1.0 to 10.0, preferably from 1.1 to 8.0 and more preferably from 1.2 to 4.5.

In the first composition, the polymer present is preferably composed of at least 1 5% by weight of the polymer as obtained in the polymerization reaction, more preferably at least 30% by weight and even more preferably at least 45% by weight. The remaining amount of polymer is composed of the further polymers mentioned above. Examples of suitable polymers are identified in WO 2009/148932 and preferably include styrene-butadiene copolymer, natural rubbers, polyisoprene and polybutadiene. It is desirable that such further polymers have a Mooney viscosity (ML 1 +4, 100 °C as measured in accordance with ASTM D 1646 (2004)) in the range of from 20 to 150, preferably from 30 to 100.

The second polymer composition according to the sixth aspect of the invention comprises the polymer of the invention, including modified polymer, and one or more fillers. The second polymer composition is typically the result of a mechanical mixing process involing the polymer of the invention and one or more fillers. It typically includes components which are added to and mechanically mixed with the polymer or first polymer composition.

The first and second polymer compositions may optionally further comprise a least one vulcanizing agent as defined further below.

The second polymer composition comprising filler can be prepared by kneading the first polymer composition., optionally comprising one or more components selected from oils, stabilizers and. further polymers, and one or more fillers in a kneader at 140 to 180 °C.

Alternatively, the second polymer composition can be prepared by kneading the first polymer composition and one or more fillers in a kneader at 140 to 180°C to form a "first stage" second composition. The formation of the "first stage" second composition may involve one or more mixing steps, preferably 2 to 7 mixing steps. After cooling, vulcanizing agents such as sulfur,
vulcanizing accelerators, optionally zinc oxide and the like are added to the "first stage" second composition, and the resulting "second stage" second composition is blended using a Brabender mixer, Banbury mixer or open, roll mill to form the desired shape.

OILS

One or more oils may be used in combination with the uncrosslinked polymer to reduce viscosity or Mooney values or to improve processabiiity of the first polymer composition and various performance properties of the (vulcanized) second polymer compositions.

Oils can be added to the polymer prior to the end of the polymer preparation process and as a separate component of the first or second polymer composition preparation process in accordance with the present teachings. For representative examples and classification, of oils see WO 2009/148932 and US 2005/0159513, each of which is incorporated herein by reference in its entirety.

Processing aids can optionally be added to the first polymer composition. They are usually added for reducing the viscosity. As a result, the mixing period is decreased and/or the number of mixing steps is reduced and, consequently, less energy is consumed and/or a higher throughput in the course of the rubber compound extrusion process is achieved. Representative processing aids are described in Rubber Handbook, SGF, The Swedish Institution of Rubber Technology 2000 and in Werner Kleemann, Kurt Weber, Elastverarbeitung-Kennwerte und Berechimngsmethoden, Deutscher Vcrlag fflr Griindstoffindiistrie (Leipzig, 1990), each of
which is incorporated herein by reference in its entirety. Examples of representative processing aids include in particular:

The second composition of the invention, comprises one or more fillers, which serve as reinforcement agents. Examples of suitable fillers include carbon black (including eiectroconductive carbon black), carbon nanotubes (CNT) (including discrete CNT, hollow carbon fibers (HCF) and modified CNT carrying one or more functional groups, such as hydroxy!., carboxyl and carbonyl groups), graphite, graphene (including discrete graphene platelets), silica, carbon-silica dual-phase filler, clays (layered silicates, including exfoliated nanoclay and organoclay), calcium carbonate, magnesium carbonate, iignin, amorphous fillers, such as glass particle-based fillers, starch-based fillers, and combinations thereof. Further examples of suitable fillers arc described, in WO 2009/148932 which is fully incorporated herein by reference, Examples of suitable carbon, black include the one conventionally manufactured by a furnace method, for example having a nitrogen adsorption specific surface area of 50-200 rrr/g and DBP oil absorption of 80-200 ml/100 grams, such, as carbon black of the FEF, I !AF, ISAF or SAF class, and. eiectroconductive carbon black. In some embodiments, high agglomeration- type carbon black is used. Carbon black is typically used in an amount of from 2 to 100 parts by weight, or 5 to 100 parts by weight, or 10 to 100 parts by weight, or 10 to 95 parts by weight per 100 parts by weight of the total polymer.

Examples of suitable silica fillers include wet process silica, dry process silica and synthetic silicate-type silica. Silica with a small particle diameter and high surface area exhibits a high
reinforcing effect. Small diameter, high agglomeration-type silica (i.e. having a large surface area and high oil absorptivity) exhibits excellent dispersibiiity in the polymer composition, resulting in superior processability. An average particle diameter of silica, in terms of the primary' particle diameter may be from 5 to 60 nm, or 10 to 35 nm. The specific surface area of the silica particles (measured by the BET method) may be from 35 to 300 rn2/g. Silica is typically used in an amount of from 10 to 100 parts by weight, or 30 to 100 parts by weight, or 30 to 95 parts by weight per 100 parts by weight of the total polymer.

Carbon black and silica may be added together, in which case the total amount of carbon black and silica is from. 30 to 100 parts by weight or 30 to 95 parts by weight, per 100 parts by weight of the total polymer.

Carbon-silica dual-phase filler is so called, silica-coated carbon black made by coating silica on the surface of carbon black and. commercially available under the trademark CRX2000, CRX2002 or C X2006 (products of Cabot Co.). Carbon-silica dual-phase filler is added in the same amounts as described above with respect to silica.

SI LANE COUPLING AGENTS

In some embodiments, a si lane coupling agent (used for compatibilization of polymer and fillers) is added to the composition comprising the polymer of the invention and silica, layered silicate (such as magadiite) or carbon-silica, dual-phase filler. The typical amount of a silane coupling agent added is from about 1 to about 20 parts by weight and, in some embodiments, from about 5 to about 15 pails by weight for 100 parts by weight of the total amount of silica, and/or carbon-silica dual-phase filler. Silane coupling agents can be classified according to Fritz Rdthemeyer, Franz Sommer: Kautschuk Technologic, (Carl Hanser Vcrlag 2006):

A vulcanizing accelerator of the sulfene amide-type, guanidine-type or thiuram-type can be used together with a vulcanizing agent as required. Other additives such as zinc white.
vulcanization auxiliaries, aging preventives, processing adjuvants and the like may optionally be added. A vulcanizing agent is typically added to the polymer composition in an amount of from 0,5 to 10 parts by weight or, in some embodiments, 1 to 6 parts by weight per 100 parts by weight of the total polymer. Examples of vulcanizing accelerators and amount thereof added with respect to the total polymer are given in WO 2009/148932.

Sulfur accelerator systems may or may not contain zinc oxide. Zinc oxide is preferably used as a component of the sulfur accelerator system..

VULCANIZED POLYMER COMPOSITION

The vulcanized polymer composition according to the seventh aspect of the invention is obtained by vulcanizing the first or the second polymer composition, which comprises at least one vulcanizing agent. Since the vulcanized elastomeric polymer compositions of the invention exhibit low rolling resistance, low dynamic heat build-up and superior wet skid performance, they are well suited for use in manufacturing tires, tire treads, side wails and tire carcasses as well as other industrial products such as belts, hoses, vibration dampers and footwear components.

The vulcanized polymer composition is the result of a reactive polymer-polymer crosslink- forming process which is performed on (i) a mixture of the polymer and at least one vulcanizing agent, (ii) the first polymer composition comprising at least one vulcanizing agent, or (iii) the second polymer composition comprising at least one vulcanizing agent. Therefore, the reactive process converts an essentially uncrosslinked polymer or an essentially uncross linked polymer composition, particularly a first polymer composition or second polymer composition each containing at least one vulcanizing agent, into a vulcanized (or crosslinked) polymer composition.

The cross-linked (vulcanized) polymer composition of the invention exhibits reduced heat build-up, reduced rebound resilience at 0°C and a good balance of physical properties, including one or more of the following: abrasion resistance, tensile strength, modulus and tear, while a composition comprising the uncrosslinked polymer (prior to vulcanization) maintains good processing characteristics. The composition is useful in preparing tire treads having lower rolling resistance, higher wet grip, higher ice grip and lower heat build-up, while maintaining good wear properties.
For a vulcanized polymer, the gel content is preferably greater than 50 weight percent, more preferably greater than 75 weight percent and even more preferably greater than 90 weight percent, based on the weight of the polymer. Gel content can be determined by dissolving 0.2 grams of polymer in 150 ml of toluene for 24 hours at ambient temperature, separating the insolubles, drying the insoiubles and measuring the amount of insolubles.

The invention also provides an article comprising at least one component formed from a vulcanized polymer composition of the invention. The article may be a tire, a tire tread, a tire side wall, an automotive part, a footwear component, a golf ball, a belt, a gasket, a seal or a hose.

For producing vehicle tires, the following further polymers arc of particular interest for use in combination with the polymer of the invention; natural, rubber; low cis polybutadiene (LCBR) comprising less than 20 percent by weight of 1 ,2-polybutadiene, emulsion SBR (ESBR) and solution SBR (SSBR) rubbers with a glass transition temperature above -50 °C; polybutadiene rubber with a high cis-l ,4-unit content (>90%). such as obtained by using catalysts based on nickel, cobalt, titanium, vanadium., gadolinium or neodymium; and polybutadiene rubber with a vinyl content of 0 to 75%; and combinations thereof; polybutadiene rubber with, a high trans- 1 ,4-unit content (>75%) or SBR containing, for example, between 5 and 45 wt% styrene and having a high trans- 1,4-polybutadiene content (>75%) in the polybutadiene fraction of the copolym.er (each type of polymer, SBR or BR, may be obtained with one or more initiator compounds comprising earth alkaline metal compounds, such, as described in U.S. Patent Nos. 6,693, 160; 6,627.715; 6,489,415; 6,103,842; 5,753,579; 5,086,136; and 3,629,213, each of which is hereby incorporated herein by reference in. its entirety; or by using catalysts based on cobalt, such as described in U.S. Patent Nos. 6310152; 5,834,573: 5,753,761 ; 5,448,002 and 5,089,574 and U.S. Patent Application Publication No. 2003/00651 14, each of which, is hereby incorporated, herein by reference in its entirety; or by using catalysts based on vanadium, such as described in. EP 1 367 069; JP 1 1301794 and U.S. 3,951,936, each of which is hereby incorporated herein by reference in. its entirety; or by using catalysts based on neodymium, such as described in EP 0 964 008, EP 0 924 214 and U.S. Patent Nos. 6,184,168; 6,018.007; 4931376; 5,134, 199 and 4,689,368, each of which is hereby incorporated herein by reference in its entirety).
The composition of the invention may also be used for producing high impact polystyrene (HIPS) and butadiene-modi fied acrylonitrilc-butadiene-styrene copolymer (ABS) (see, for example, WO 2009/148932, incorporated herein by reference). DEFINITIONS

Unless specifically indicated otherwise, the expression "polymer" as used herein is intended to encompass both unmodified polymer and modified (i.e. chain end-modified) polymer.

Alkyl groups as defined herein, whether as such or in association with other groups, such as alkylaryl or alkoxy, include both straight chain alkyl groups, such as methyl (Me), ethyl (Et), n- propyl (Pr), n-butyl (Bu), mpentyl, n-hexyl, etc, branched alkyl groups, such as isopropyl, tert- butyl, etc. and cyclic alkyl groups, such as cyclohexyl.

Aryl groups as defined herein include phenyl, biphenyl and other benzenoid compounds. Aryl groups preferably contain only one aromatic ring and most preferably contain a Q aromatic ring.

Alkylaryl groups as defined herein refer to a combination of one or more aryl groups bound to one or more alkyl groups, for example in the form of alkyl -aryl, aryl-alkyl, alkyl-aryl-a!kyl and aryl-alkyl-aryl. Alkylaryl groups preferably contain only one aromatic ring and most preferably contain a C6 aromatic ring.

EXAMPLES

The following examples are provided in order to further illustrate the invention and are not to be construed as limiting. They include the preparation of the polymerization initiator; the preparation of sulfanylsilaiie chain end modifying agent; the preparation, and testing of polymers; and the preparation and testing of uncrosslinked polymer compositions, including the first and second polymer compositions, as well as of cross-linked or cured polymer compositions, also referred to as vulcanized polymer composition. Unless stated otherwise, all parts and percentages are expressed on a weight basis. The term "overnight" refers to a time of approximately 16- 18 hours. "Room temperature" refers to a temperature of about 20°C. The
polymerizations were performed under exclusion of moisture and oxygen in a nitrogen or argon atmosphere. The vinyl content in the conjugated diolefm part of the polymer chain was determined by IR absorption spectrometry (Morello method, IFS 66 FT-IR spectrometer of Bruker Analytic GmbH). The IR samples were prepared using CS2 as swelling agent.

FT-IR spectrometer of Bruker Analytik GmbH). The IR samples were prepared using CS2 as swelling agent. For the IR determination of the bound styrene in styrene-butadicne copolymers, four bands are assessed: a) band for trans- 1 ,4-polybutadiene units at 966 em" 1, b) band for cis- 1 ,4-polybutadiene units at 730 cm'1, c) band for 1 ,2-polybutadiene units at 91 0 cm"1 and band for bound styrene (styrene aromatic bond) at 700 cm" 1. The band heights are normalized according to the appropriate extinction coefficients and summarized to a total of 100%. The normalization is done via Ή- and I 3C-NMR. The styrene content was alternatively determined by NMR (Avance 400 device (Ή = 400 MHz; 13C = 100 MHz) of Bruker Analytik GmbH).

The I D NMR spectra were collected on a BRUKER Avance 400 NMR spectrometer (BRUKER BioSpin GmbH) using a 5 mm dual detection probe. The field homogeneity was optimized by maximizing the deuterium lock signal. The samples were shimmed by optimizing the deuterium, lock signal. The samples were ran at room temperature (298 K). The following deuterated solvents were used: C6D6 (7.16 ppm for Ή; 128.06 ppm for , 3C-NMR), CDC'b (7.24 ppm for Ή; 77.03 ppm for 13C-NMR)5 the signals of the remaining protons of deuterated solvents were each used as an internal reference.

For spectral processing, the BRUKER I D WINNMR software (version 6.0) was used. Phasing, base line correction and spectral integration of the resulting spectra was done in the manual mode. For acquisition parameters see Table 1 .

About 12-14 mg dried polymer sample (moisture content <0.6%) was dissolved in 10 mL tetrahydrofuran using a brown vial of 10 ml. size. The polymer was dissolved by shaking the vial for 20 min at 200 u/min.

b) Polymer solution was transferred into a 2 ml vial using a 0.45 itm disposable filter. c) The 2 ml vial was placed on a sampler for GPC analysis.

Polydispersity (Mw/Mn) was used as a measure of molecular weight distribution. The calculatio of Mw (weight average molecular weight) and Mn (number average molecular weight) was based on one of two procedures.

Mpl . M.p2, Mp3 correspond to the (maximum peak) molecular weight measured at the fust, second or third peaks of the GPC curve [the first peak Mpl (lowest molecular weight) is located on the right side of the curve and the last peak (highest molecular weight) is located on the left side of the curve], respectively. Maximum peak molecular weight means the molecular weight of the peak at the position of maximum peak intensity. Mp2 and Mp3 are two or three polymer chains coupled to one macro molecule. Mpl is one polymer chain (base molecular weight - no coupling of two or more polymer chains to one macromolecule). The total
coupling rate represents the sum of the weight fractions of coupled polymers relative to the total polymer weight, including the sum. of the weight fractions of all coupled polymers and the uncoupled polymer. The total coupling rate is calculated as:

The oil content in the oil extended polymers was determined by extraction method according to ASTM D 5574-95 using a microwave extraction apparatus (MARS from CEM) and a sample weight of l g. The extracted rubber sample was dried at 140°C for 30 minutes.

Mooney viscosity was measured according to ASTM D 1646 (2004), with a preheating time of one minute and a rotor operation time of 4 minutes, at a temperature of 100°C [ML 1 +4( 100 °C)], on a MV 2000E from Alpha Technologies UK. The rubber Mooney viscosity measurement is performed on dry (solvent free) raw polymer (unvulcanized rubber). The Mooney values of the raw polymers are listed in Table 3. The Compound Mooney viscosity is measured on an unc ed (un vulcanized) second state polymer compound sample prepared according to Table 4. The Compound Mooney values are listed in. Table 5.

Measurement of unvulcanized rheological properties was performed according to ASTM.' D 5289-95 (reapproved 2001), using a. rotor-less shear rheometer (MDR 2000 E from Alpha Technologies UK) to measure Time to Cure (TC). The rheometer measurement was performed at a constant temperature of 160°C on an non- vulcanized second stage polymer formulation, according to Table 4. The amount of polymer sample is about 4.5 g. Sample shape and shape
preparation are standardized and defined by the measurement device (MD 2000 E from Alpha

Technologies UK), The TC 50 and TC 90 values are the respective times required to achieve 50% and 90% conversion of the vulcanization reaction. The torque is measured as a function of tinie of reaction. The vulcanization conversion is automatically calculated from the generated torque versus time curve. The TS 1 and I S 2 values are the respective times required to increase the torque by 1 dNm and 2 dNm. above the respective torque minimum (ML) during vulcanization.

Tensile Strength, Elongation at Break and Modulus at 300% Elongation (Modulus 300) were measured according to ASTM D 412-98 A (reapproved 2002), using a dumbbell die C test piece on a Zwick Z010. Of the standardized dumbbell die C test pieces, those of 2 mm thickness were used. The tensile strength measurement was performed at room temperature, on a cured (vulcanized) second stage polymer sample, prepared according to Table 4. Stage 2 formulations were vulcanized within 16-25 minutes at 160°C to TC 95 (95% vulcanization conversion) (see cure data in Table 5).

Heat build-up was measured according to ASTM D 623, method A, on a Doli Goodrich Flexometer. The measurement was performed on a vulcanized second stage polymer samples according to Table 5, Stage 2 formulations were vulcanized at 160°C to TC 95 (95% vulcanization conversion) (see cure data in Table 5).

Rebound resilience was measured according to DIN 53512 at 0°C and 60°C on a Zwick 5109.

The measurement was performed on a cured (vulcanized) second stage polymer sample, prepared according to Table 4. Stage 2 formulations were vulcanized at 160°C to TC 95 (95% vulcanization conversion) (see cure data in Table 5). The smaller the index at 0°C, the better the wet skid resistance (lower = better). The larger the index at 60°C, the lower the hysteresis loss and lower the rolling resistance (higher = better).

DIN abrasion was measured according to DIN 53516 (1987-06-01). The larger the index, the lower the wear resistance (lower = better). The abrasion measurement was performed on a vulcanized, second stage polymer formulation according to Table 5.

In general, the higher the values for Elongation at Break, Tensile Strength, Modulus 300 and rebound resilience at 60°C} the better the sample performance; whereas the lower the Heat
Build-Up, rebound resilience at 0°C and Abrasion, the better the sample performance. Preferably TS 1 is > 0.5 minute, TS 2 is > 1 .5 minutes, TC 50 is from 3 to 8 minutes, and TC 90 is from 8 to 1 minutes.

5 Modifier Preparation: Four polymerization initiator precursor compounds (PI to P4)} four polymerization initiators (II to 14) and two chain end modifying agents were used. Polymerization initiator precursor compounds P I to P4 and polymerization initiators II, 12. 13 and 14 are in accordance with the invention.

A typical initiator mixture comprising II, such as used in the preparation of Example 2 in Table 2, was prepared as follows. The precursor compound PI (36.9 g, 1 00 mmol) was dissolved in 400 ml cyclohexane. TMEDA (40,7 g, 350 mmol) and ii-BuLi. (63.4 g, 200 mmol, 20 wt% solution in cvclohexane) were added. The color of the solution immediately turned dark red indicating the formation of the dianion II . Due to the very high air and moisture sensitivity of II, the compound was characterized as its hydrolyzed product Il a. Therefore, a sample of the initiator mixture was hydrolyzed with an excess of methanol and characterized by NM'R and GC-MS.

The preparation of the initiator mixtures comprising the compounds Ι2-Ϊ4 were performed in situ according to the procedure described for II above. The structures for 12, 13 and 14 are depicted, below.

Chain End Modifying Agents

Chain End Modifying Agent Et was prepared by two preparation pathways as follows:

<MeO)2— Si "~ S— Si(Me)2C(Me)3

Me

El

Preparation Pathway 1 (El):

To a 100 mL Schlenk flask was charged 25 ml tetrahydrofuran (THF), 79,5 mg (1 0 mmol) lithium hydride, and subsequently, 1 . 1 8 g ( 10 mmol) gamma-mercapiopropyi (methyl) dimethoxysilane from, the ABCR GmbH. The reaction mixture was stirred for 24 hours at room temperature, and another two hours at 50°C. Than tert-butyl dimethyl, chloro silane (1 .51 g (1 0 mmol)) was dissolved in 10 g THF, and the resulting solution, was then added drop wise to the Schlenk flask. Lithium chloride precipitated. The suspension was stirred for about 24 hours at room, temperature, and for another two hours at 50°C. The THF solvent was removed under vacuum. Then cyclohexane (30 ml) was added. The white precipitate was subsequently separated by filtration. The cyclohexane solvent was removed under vacuuni (under reduced
pressure). The resulting colorless liquid solution proved to be 99% pure per GC, and therefore no further purification was necessary. A yield of 3.1 g (9.3 mmol) of chain end-modifier agent El was obtained. Preparation Pathway 2 (El):

To a 100 niL Schlenk flask was charged 1.18 g (10 mmol) gamma-mercaptopropyl (methyl) dimcthoxysUane from the ABCR GmbH, 25 ml tetrahydrofuran (THF), and subsequently, 0.594 g (1 1 mmol) sodium, methanolate (NaOMe) dissolved in 10 niL TFIF, The reaction mixture was stirred for 18 hours at room temperature. Then tert-butyl dimethyl chloro silane (1.51 g (10 mmol)) was dissolved in 10 g THF, and the resulting solution was then added drop wise to the Schlenk ilask. Sodium chloride precipitated. The suspension was stirred for about 24 hours at room temperature, and for another two hours at 50°C. The THF solvent was removed, under vacuum. Then cyclohexane (30 ml) was added. The white precipitate was subsequently separated by filtration. The cyclohexane solvent, was removed under vacuum (under reduced pressure). The resulting colorless liquid solution proved to be 89% pure per GC. Further purification consisted, in a fractionated distillation, and a yield of 2.6 g (7.9 mmol) of chain-end modifier agent El was obtained.

Chain End Modifying Agent E2 was purchased as N,N-dimethyi-3- aminopropylmethyldimethoxysilane from ABCR GmbH.

E2

Randomizers

TMEDA (N,N,N%N'-Tetramethyl-ethylene-l ,2-diamine) was purchased from Sigma-Aldrich and was dried over molecular sieve prior to use.

Copolymerization of 1 ,3-Butadiene with Styrene (Examples 1 -1 1 )

The co-polymerizations were performed, in a double wall, 1.0 liter steel reactor, which was first purged with nitrogen, before the addition of organic solvent, monomers, polar coordinator compound, initiator compound or other components. The polymerization, reactor was tempered to 60°C, unless stated otherwise. The following components were then added in the following order: cyclohexane solvent (4600 grains); butadiene monomer, styrene monomer,
tetramethyletfaylene diamine (TMEDA) and optionally divinylbenzene (DVB; Bowden Chemicals Ltd.; 0.16 M solution in cyclohexane; 1 ,3-DVB/l ,4-DVB=70/30), and the mixture was heated to 40°C, followed by titration with n-butyl lithium to remove traces of moisture or other impurities. The desired polymerization initiator compound was added into the polymerization reactor to initiate the polymerization reaction. The polymerization was performed for 80 minutes, not allowing the polymerization temperature to exceed 60°C. Afterwards. 2.3% of the total butadiene monomer amount was added, followed by the addition of the chain, end modifier, unless stated otherwise. After 20 minutes the polymerization was terminated by the addition of methanol {2 equivalents based on initiator). To the polymer solution, 2.20 g IRGANOX 1520 was added as a stabilizer. This mixture was stirred for 10 minutes. Optionall TDAE oil was added and the resulting polymer solution (Examples 10 and 1 1 , Table 2 and Table 3) was stirred for 30 minutes to ensure homogenous distribution of the oil. The resulting polymer solution was than stripped with steam for one hour to remove solvent and other volatiles, and dried in an oven at 70°C for 30 minutes and then additionally for one to three days, at room temperature. The resulting polymer composition and several of its properties are summarized in Table 3 below. Unless otherwise stated, quantities are expressed in mmois.

Unless indicated otherwise, monomer conversions of more than 99% by weight were achieved for all experiments listed in Table 2. Monomer conversion was measured as polymer solid content representing the weight of polymer after removal of the polymerization solvent and any volatile components. The corresponding polymer solution sample was taken from the polymerization reactor shortly prior to termination of the polymerization process. A dash "-" in the tables indicates that no constituent was added. "N.M." indicates that no measurement was taken, or that corresponding data was unavailable.

B: vinyl content is that of the 1 ,2-polybutadiene unit content of the final copolymer, and is detemiiiied by IR Spectroscopy

C; styrene content of the final copolymer, and is determined by I R Spectroscopy

Polymer Compos it ions

Polymer compositions were prepared by combining and compounding the constituents listed below in Tabic 4 in a 380 ml Banbury mixer and vulcanized at 160°C for 20 minutes. Viilcanization process data and physical properties for each composition example are provided in Table 5 and Table 6.

Surprisingly, it was found that the initiator compounds of the invention produce polymers which can be used for the preparation of polymer compositions and vulcanized polymer
compositions. The vulcanized (or cured) polymer compositions based on polymers made by using the initiator compounds of the invention (see for example 2A in Table 6) have a relatively low (or reduced) rebound resilience at 0°C; relatively decreased tire heat build-up and relatively decreased DIN abrasion, when compared with vulcanized elastomeric polymer compositions based on polymers not made with a polymerization initiator compound of the invention (see example! A in Table 5 and Table 6). Exemplary vulcanized composition 2A, which is based on polymer 2, prepared from initiator II of the invention, has a heat build-up value of 1 1 .4°C while vulcanized composition 1A, based on non-modified polymer 1 , formed from tt-butyl lithium initiator, has a relatively higher heat build-up value of 124.1°C and a relatively higher DIN abrasion value of 150 mm3 (compared to 13 mm3 of compound 2 A).

A first polymer composition of the invention may be converted into a second polymer compositions (first stage mixing [mixing step in which silica filler is added to polymer] and second stage mixing according to Table 4, involving silica filler and polymer of the invention), then further converted into a vulcanized polymer composition, for example by curing the second stage mixing result according to Table 4 at ! 60°€ for 20 min as described herein. The second polymer compositions and vulcanized polymer compositions (as listed in Table 4 and Table 5) prepared under identical conditions at the same day by the identical operator are identified with the capital, letter A, The polymer contained, in. the vulcanized polymer composition is identified by the polymer number, e.g. 1 , 2, ect. As a result, there is one vulcanized polymer composition series (including compositions 1 A, 2Λ, 3 A, 4A and 5.A) which can be directly compared, with each other.

In accordance with the invention, the combination of the initiator compounds such as I I , 12. 13 or 14 with, one or more chain-end. modifying compounds such as El or E2 and optionally with a coupling agent leads to the formation of the polymers of the invention, which have relatively lower heat build-up under mechanical, stress, lower rebound resilience at 0°C values and lower abrasion resistance when present in vulcanized polymer compositions, compared with polymers in comparative vulcanized polymer compositions not containing polymers made by using polymerization initiator compounds of the invention.

As shown in Table 5, "heat build-up" during dynamic deformation, rebound resilience at 0°C, compound Mooney and DIN abrasion of the vulcanized polymer compositions comprising modified polymers of the invention is reduced. Polymer "heat build-up" reduction is believed
to improve the durability of the resulting vulcanized polymer composition, to reduce the vulcanizate hysteresis energy loss, leading to a decreased rolling resistance, to increase overall elasticity and to improve handling characteristics of a tire. A low DIN abrasion value indicates increased vulcanizate durability and abrasion resistance. Decreased rebound resilience at 0°C of the vulcanized polymer composition compared with vulcanizates comprising reference (non- inventive) polymers indicate improved grip properties on a wet surface. "Compound Mooney" values of non-cured first or second polymer compositions are decreased or at least in a similar range compared with polymer compositions comprising reference polymers; a reduced compound Mooney indicating a reduced polymer composition viscosity and leads to a more economic mixing process (e.g. mixing polymer with fillers and additives). "Tensile Strength" and "Modulus 300" are not or not significantly deteriorated in comparison with the reference polymer, suggesting the formation of a stable polymer network with a higher resistance under mechanical stress. More specific vulcanizates comprising polymers prepared from modified initiator compounds according to the invention in combination with chain-end modifiers (Example 5 A, Table 6) leads to an increasing of the values of Tensile strength and Modulus 300, indicationg an improved interaction with the silica filler compared with vulcanizates comprising reference polymers (Example 1A, Table 6). Although some "Elongation at Break" values are slightly reduced, they are still very acceptable considering the degree of improvement of the heat build-up and abrasion resistance values.

The effect of SSBR-silica vulcanizates according to the invention is further substantiated as follows. The vulcanizate comprising a polymer made by a combination of the polymerization initiator compound II , prepared from the precursor PI , n-butyl lithium and TMEDA, in Example 2A of Table 5 has relatively lower heat build-up and DIN abrasion as compared to the counterpart example 1 A prepared without the polymerization initiator compound. According to Table 6, the cured (vulcanized.) polymer composition of the invention 2 A has a lower rebound resilience at 0°C than the counterpart Example 1 A, prepared without the polymerization initiator compound. Furthermore, modified SSBR-silica vulcanizates comprising a polymer made by a combination of the polymerization initiator compound II , prepared from the precursor P I , n-butyl lithium and TMEDA, with chain end modifying agent El in Example 5 A of Table 5 has relatively lower heat build-up and DIN abrasion as compared to the counterpart examples prepared without polymerization initiator compound (Example 1 A) and prepared with polymerization initiator compound, but wi.th.out chain end modifying agent (Examples 2 A. 3 A, 4 A). According to Table 6, the vulcanized polymer composition of the invention 5A
comprising polymer 5, made by using polymerization initiator I I and chain end modifying agent E l , has a lower rebound at 0°C, a higher rebound at 60°C and a higher Modulus 300 compared to the counterpart examples prepared without polymerization initiator compound. (Example 1 A) and prepared with the polymerization initiator compound, but without chain end modifying agent (Examples 2A, 3 A, 4A). Accordingly, the polymerization initiator of the invention in combination with an efficient chain end modifying agent (e.g. E l ) improves the specified vulcanized polymer composition properties as compared to other compositions not containing an initiator of the invention or containing an initiator of the invention, but not containing a chain end modifying agent.

Claims

A polymerization initiator represented by the following Fo:

Formula 1 ,

or Lewis base ad ducts thereof,

wherein

each M! is independently selected from lithium, sodium and potassium;

each is independently selected from (CpCioo) alkyl and (C2-C100) alkeny!, optionally substituted with one or more (C(y-C\2) aryl groups and optionally linked to the carbon atom C by up to 25 monomer units selected from conjugated diene monomers and aromatic vinyl compounds, especially butadiene, isoprene and styrene;

Y2 is selected from a nitrogen atom, a sulfur atom and a silicon atom; R6, R and R8 are each independently selected from (Ci-Cig) alkyl, di(Ci-C6) alkyl amine (only when Y2 is a silicon atom ), (Ce-Cn) aryl, (C7-Cig) aikylaryl and, when Y2 is not a silicon atom, -SiR1 7R, RR19, wherein R 1 7, R18 and R19 are each independently selected from (Cr Cig) alkyl. (C6-C|g) aryl and (C7-Cig) aikylaryl; q and r are each an integer selected from 0 and 1 ; and q+r=T when Y =N, q=r=0 when Y =S, and q+r=2 when Y -Si;

2. The polymerization initiator according to claim. 1 which is represented by the following Formula 5 :

Formula 5.

or a Lewis base adduct thereof,

wherein.

M1 is lithium;

each R1 is independently selected from (C | -C|g) alkyl;

p is an an integer selected from 1 , 2 and. 3:

is selected from nitrogen and >C-H; and

all other substituents or groups are as defined for Formula 1 in claim 3

3. The polymerization initiator according to claim 2, wherein,

each R1 is independently selected from (CpC?) alkyl:
R " is hydrogen;

R3, R4 and R5 are each independently selected from (Ci-Cio) alkyl and, when Y1 is not a silicon atom, -SiRl 4RI SR, 65 wherein R14, Rt s and R16 are each independently selected from (C]-C16) alkyl; and

R6, R7 and R8 are each independently selected from (Cj-Cio) alkyl and, when. Y2 is not a silicon atom, -SiR17R%19, wherein R17, R18 and R19 are each independently selected from. (Ci-Cie) alkyl,

4. The polymerization initiator according to claim 2, wherein

each. R1 is independently selected from (C|-Cio) alkyl;

R12 is hydrogen;

R\ R4 and 5 are each independently selected from (CrC]g) alkyl and, when Y1 is not a silicon atom, -SiR, 4R.l sR16, wherein RH, R1 and R16 are each independently selected from (C,-C10) alkyl;

R6, R7 and R8 are each independently selected from (CrC! 8) alkyl and, when Y2 is not a silicon atom, -Si. i7R, 8R! 9, wherein 17, R18 and R19 are each independently selected from (Ci-Cl0) alkyl;

m. and p are each independently selected from, an integer of 1 and 2. 5. The polymerization initiator according to claim 1 which is represented by the following Formula 6:

Formula 6,

or a Lewis base adduct thereof.,

wherein

M1 is lithium.;

each R.1 is independently selected from (C |-Cio) alkyl;

R12 is hydrogen;
R3, R4 and Rs are each independently selected from (Cj-Cig) alkyl and, when Y! is not a silicon atom, -SiR14R, 5R16, wherein R14, R 15 and R16 are each independently selected from. (C rC io) alkyl;

m and p are each independently an integer selected from 1 and 2;

R6, R7 and R8 are each independently selected from. (CrQ g) alkyl and, when Y2 is not a silicon atom, -SiRl 7Rl 8R19, wherein. R17, R18 and R19 are each, independently selected, from (CrCi0) alkyl; and

all other substituents or groups are as defined for Formula 1 in claim. 1.

13. The method according to claim 12, wherein the at least one type of polymerizable monomers is selected from 1 ,3 -butadiene, isoprene and styrene.

14. The method according to claim 12 or 13, further comprising a step of reacting the polymer with one or more chain end modifying agents so as to provide a chain end-modified polymer.

1 5. The method according to claim 14, wherein the one or more chain end modifying agents are represented by the following Formulas 8, 9, 10, 1 1 , 12, 13, 14, 15 and 16 and Lewis base adducts thereof:

Formula 8

wherein M3 is a silicon atom or a tin atom;

T is at least divalent and is selected from (C6-C|8) aryl, (Cr-Cw) alkylaryl and (Cj-Cig) alkyl, wherein each group is optionally substituted with one or more groups selected from difCi-C6 hydrocarbyl)amino, bis(tri(Ci-Ci2 alkyl)silyl)amino, tns(CrC7 hydrocarbyl)silyl, (C7-C is) alkylaryl and (Ce-Cig) aryl;

50 is at least divalent and is selected from (C()-Cis) aryl, (tyCig) alkylaryl and (Cj-Cjg) alkyl, wherein each group is optionally substituted with one or more groups selected from di(Cj-C? hydrocarbyl)amino, bis(tri(Ci-C i2 alkyl)silyl)ammo, tris(Ci-C7 hydrocarbyl)silyl} (C7-Ci g) alkylaryl and (C C jg) aryl.

1 6. A polymer or chain end-modi.fi.ed polymer obtainable by process as defined in any one of claims 1 2 to 15.

17. A polymer composition comprising the polymer or chain end-modified polymer as defined in claim 16 and one or more further components selected from (i) components which are added to or formed as a result of the polymerization process used for making said polymer and (ii) components which remain after solvent removal from the polymerization process.

1 8. The polymer composition according to claim 17. comprising one or more components selected from extender oils, stabilizers and further polymers.

1 9. The polymer composition as defined in claim 17 or 18, further comprising one or more fillers.

21. The polymer composition as defined in any one of claims 17 to 20, further comprising one or more vulcanizing agents. 22. A vulcanized polymer composition which is obtained by vulcanizing the polymer composition as defined in claim 21 .

23. A method of making a vulcanized polymer composition, comprising the step of vulcanizing the polymer composition as defined in claim 22.

24. An article comprising at least one component formed from the vulcanized polymer composition as defined in claim 23.